This disclosure is related to application Ser. No. 08/236,390. The present disclosure is directed to a drill pipe spinner and more particularly to a drill pipe spinner which is adapted for use in handling drill pipe of several specified size. The device includes an upwardly directed hanger assembly supporting a pair of spaced plates which encompass an assembly enabling a drill pipe to be grasped by left and right drive rollers which are held snugly against the drill pipe by left and right pressure rollers. The pressure rollers are mounted on bell crank mechanisms which swing out of the way to open the equipment so that the drill pipe can be inserted, and which swing inwardly to position the pressure rollers against the drill pipe so that the drill pipe is forced against the drive rollers. This forms a clamping mechanism which is able to clamp the drill pipe with four regions of contact. Two regions of contact include the drive rollers, duplicated symmetrically on the left and right, and the remaining two areas of contact are the pressure rollers. As a generalization the drill pipe is snugly held so that it is driven in a specified direction for threading or unthreading of the drill pipe. This accommodates pipe of a large range of diameters using an improved bell crank mechanism.
In drilling for oil and gas, it is necessary to assemble a suing of drill pipe joints. The string of drill pipe is suspended by the overhead derrick. As the well is drilled deeper, it is necessary to periodically add another joint of drill pipe. Drill pipe normally comes in standard lengths, a typical length being 30 feet. Drill pipe normally is threaded into the drill string so that the drill string can be deepen to extend the well. In doing this, the drill pipe added to the string is incorporated at the wellhead by connection between the drill string that is already in the well borehole and is threaded below the Kelley. The Kelley is the driving element which cooperates with a powered rotary table. The Kelley is formed of a non-round shape and extends through a matching hole in the rotary table. This permits the Kelley to travel upwardly and downwardly so that the Kelley is able to drive the drill string from rotation imparted by the rotary table.
The present apparatus is a system which incorporates an air motor connected with a suitable gear box. The air motor in turn is provided with a flow of air which operates the air motor and which therefore rotates a sprocket at the end of the gear box and air motor. The sprocket drives a belt or chain. The chain extends to drive sprockets which are mounted in on shafts for rotating the two drive rollers.
One important aspect of the present apparatus is the incorporation of an air cylinder which is pivotally mounted at one end and which has a piston rod extending from the other end. The piston rod is constructed so that it connects with a sleeve which in turn is joined to a bell crank mechanism pivotally mounted with the sleeve.
The bell crank mechanism is rotated so that the bell crank rotates toward and away from the drill pipe to provide clamping motion. The bell crank is able to hold a range of drill pipe sizes.
Going now to one aspect of the present disclosure, it is particularly useful in providing a wide grip on the drill pipe. After drill pipe has been used for a while the scuffed external surface is highly irregular. The present system sets forth a means and mechanism by which the drill pipe is grasped on a relatively wide roller. The roller is wide so that the grip on the roller can be readily spread over an area to assure that the external surface of the drill pipe is frictionally engaged, thereby preventing slippage, and enabling the drill pipe to be rotated.
In general terms, the present apparatus is therefore summarized as an inverted U-shaped hanger which extends upwardly above a pair of mounting plates. The hanger connects to the upper mounting plate. The upper mounting plate has an area which supports a housing which encloses an air motor connected with an integrally constructed gear box for rotating a shaft which drives a sprocket. The sprocket engages a flexible chain or belt which is looped operatively through an pressure sprocket and drive sprocket. Actually, two drive sprockets are included. The two drive sprockets are located in spaced relationship to each other to position two drive rollers which bear against a drill pipe. In addition to the foregoing, the equipment includes a pair of pressure rollers which are similar to the drive rollers. The two pressure rollers are independently mounted. They are mounted so that they swing outwardly, opening the throat of the tool for insertion of a drill pipe. They swing inwardly to close thereby enabling the drill pipe to be grasped. They are incorporated in the system so that the drill pipe can be grasped or clamped by the two pressure rollers. This movement is accomplished through the use of a horizontally directed air cylinder which is supported below the top mounting plate and above a bottom mounting plate. At one end it is pivotally mounted by means of a pivot connection to the cylinder housing. The opposite end incorporates an extendible piston rod which is directed outwardly to a clevis mounted on a shaft. The piston rod connects with the clevis to rotate a sleeve and thereby rotate upper and lower parallel bell crank arms. The two arms are parallel to support a pressure roller at the end of the two parallel arms. They are pivotally mounted to thereby permit movement of the bell crank. The bell crank is constructed with a fixed pivot point so that the outer end of the bell crank rotates in an arc to bring the pressure roller on it against the pipe to create a clamping force. Duplicate pressure rollers are included.
The bell crank is constructed with multiple pin insert locations. The enables the clevis on the end of the piston rod to be moved. When moved, this changes the angle of rotation of the piston rod. This changes the pivot connection between the piston rod and bell crank. This changes the leverage and thereby enables the bell crank and pressure roller to grasp at a desirable angle and thereby enable a large diameter pipe to be grasped when positioned at one insert location and a smaller pipe to be grasped when connected at another point.
The duplicate pressure rollers are enabled to grasp many sizes of pipe. The drill pipe can cover a wide range using the features of the present disclosure. By making this provision in the bell crank construction, drill pipe as small as three and one half inch is grasped. It also can accommodate drill pipe as large as seven inches. The pipe spinner apparatus can be used with tubing. Tubing has nominal dimensions of two and three eighths inches or two and seven eighths inches. Accordingly, this system can be used with both tubing and drill pipe and can thereby accommodate a very large range of pipe sizes.